Optical receiver

An optical receiver comprising:

• a circuit board having a first side, a second side opposite to the first side, a first grounding pattern, a second grounding pattern, and a signal line, the first grounding pattern and the second grounding pattern being formed on the first side separately from each other, the signal line being formed on the first side;
• a base member having an insulating body, a first wiring pattern, and a second wiring pattern, the first wiring pattern and the second wiring pattern being formed on a third side of the insulating body, the base member being disposed between the first grounding pattern and the second grounding pattern on the first side of the circuit board;
• a photodetector having a first electrode and a second electrode, the photodetector being mounted on the third side of the base member, the first electrode being electrically connected to the first wiring pattern, the second electrode being electrically connected to the second wiring pattern;
• a transimpedance amplifier having a fourth side, a first pad, and a second pad, the first pad and the second pad being formed on the fourth side, the transimpedance amplifier being mounted on the first grounding pattern of the circuit board, the first pad being electrically connected to the signal line through a first wire, the second pad being electrically connected to the first wiring pattern through a second wire;
• and
• a capacitor having a third electrode and a fourth electrode, the capacitor being mounted on the second grounding pattern, the third electrode being electrically connected to the second wiring pattern, the fourth electrode being electrically connected to the second grounding pattern,
• wherein the first wiring pattern and the second wiring pattern are apart from the first grounding pattern and the second grounding pattern in a plan view of the first side of the circuit board, and
• the first grounding pattern is electrically connected to the second grounding pattern through at least one of a third grounding pattern and a fourth grounding pattern, the third grounding pattern being formed on the first side and being apart from the first wiring pattern and the second wiring pattern in the plan view of the first side, the fourth grounding pattern being formed at least in an inside of the circuit board or on the second side of the circuit board.